Ore-roasting furnace.



lB. HALL.

ORE EOASTING PURNGE.

APPLICATION FILED MAY 5, 1909.

Patented Jan.4, 1910.

'mill/l1 UNTED STATES PATENT FFE.

BENJAMIN HALL, 0F NEVADA CITY, CALIFORNIA.

ORE-ROASTING FURNACE.

To all whom it may concern:

Be it known that I, BENJAMIN HALL, citizen of the United States,residing at Nevada City, in the county of Nevada and State ofCalifornia, have invented new and useful Improvements in Ore-RoastingFurnaces, of which the following is a specification.

This invention relates to ore roasting furnaces of the reverberatorytype, and per-4 tains particularly to a furnace in which the ore in theform of concentrates, is conveyed across a hearth by a system ofmechanically operated rabbles.

In the usual type of roasting furnace, the rabbling mechanism travelsfrom one end of the hearth to the other, which for perfect roasting isobjectionable as the rabbles carry adhering unroasted material from thefeed end of furnace to the discharge end which renders it impossible toobtain the desired perfect roast; furthermore the rabbling mechanism iseither exposed to the heat of the furnace, or is placed in closeproximity thereto, requiring` a long slotted wall, to seal which in asatisfactory manner has proved a diiiicult and in most cases anunsatisfactory procedure.

'lhe object of my invention is to overcome these defects which laccomplish by having the rabbles swing as a pendulum across the furnace,and obtain the required movement of the roasting material from one endof furnace to the other by the shape or form of shoes or rabbles whichare tapered, the wider and thicker end of shoe being toward the feed endof furnace; as the shoes or rabbles pass through the material it slidesgently toward the smaller end from where it passes on to the adjoiningshoe, and so on until it reaches the discharge end, where it passes outroasted to any condition required.

Another object is to provide a continuous, automatically operated,ore-roasting furnace of simple construction, in which the ores to betreated will receive a thorough and perfect roast, being fed into thefurnace and discharged therefrom continuously instead of intermittentlyas at present.

The invention consists of the parts and the construction and combinationof parts as hereinafter more fully described and claimed, havingreference to the accompanying drawings, in which- Figure l is alongitudinal section of the Specification of Letters Patent.

Application filed May 5, 1909.

Patented Jan. 4, 1910.

Serial No. 494,123.

invention. Fig. 2 is a transverse section on line X-X, Fig. l. Fig. 3 isa detail view of the pendulum. Fig. 4 is a detail of a rabble. Fig. 5 isa transverse view of a furnace with double hearth.

In the drawings, A is a furnace body of suitable size, shape andconstruction, in which is constructed a roasting-chamber 2 having atransversely concaved hearth 3. A feed hopper 4 is provided at one endthrough which ore is delivered to the roasting chamber 2. The admissionof the ore being suitably controlled according to the capacity of thefurnace by appropriate means as the gate 4. An outlet or dischargeopening is shown at 5 at the opposite end of the roasting chamber. Thisdischarge opening is provided with a door or gate 6 by which the airfeed and draft in the roasting chamber may be regulated. Vents 7 areprovided at intervals in the arch of the roasting chamber to facilitatethe draft.

Rabbles or shoes 9, triangular in crosssection and tapered lengthwise,are removably attached to pendulum arms l0 by means of wedge keys llengaging in slots l2 on the lower horizontal members of the pendulumslO. rlhe pendulums lO with the rabbles S) are adapted to be swungtransversely over the concave hearth 3, the bottom face of the rabblesbeing suspended just out of contact with the hearth, and with thenarrower tapered ends of the rabbles pointing toward the discharge end.

Slots B are provided in the arch of the chamber 2 through which thependulums l() pass. The Lipper outer edges of this slot B are segmentalin form, on a radius corresponding to the p'ivot of the pendulum, and asegmental piece of sheet iron 13 is secured to each pendulum stem, whichis adapted to slide in contact with the mouth ofthe slot B, so that asthe pendulum swings lengthwise in the slot, the segment 13 will act as acover and keep the slot B closed at all times, and so retain the heatand fumes within the furnace.

The pendulums 10 are secured to shafts 14 mounted in bearings l5. Inthis case l have shown the pendulums as mounted in pairs on each shaft,but it is obvious that the number may be increased or decreased withoutaltering the scope of the invention, and that as many pendulums may beemployed as the occasion requires.

Shafts 16 operated by eccentrics 17 driven by any suitable means, areconnected with the pendulums 10 in such manner that as the eccentricsare rotated, the pendulums will be swung backward and forward'across theroasting chamber 2.

rThe pendulums 10 are constructed of metallic tubes, as shown in F ig.3, and are connected with a cold air or water supply by means offlexible hose 1S, the object of which is to introduce a cooling mediuminto the pendulums, thereby greatly increasing their durability.

In operaticn, the ore to be roasted is introduced through the hopper -Ltinto the roasting chamber 2, and `falls upon the hearth 3. The pendulumsl0 are set in motion by driving the eccentrics 1T at suitable speed.This causes the rabbles 9 to pass through the ore, thereby spreading itover the surface of the hearth 3 to be acted upon by the heat ofthefurnace. The triangular and tapered or pyramidal shape of the rabblesoperates to "carry the vore forward over the hearth 3, at the same timeturning it over and `agitatin-g it, so that it is completely exposed tothe roasting action. The pyramidal form of the rabbles, theirarrangement, and their operation at right angles to the travel 0f theore gently works the ore forward to lthe final point of discharge.

To facilitate the forward movement of the ore, the pendulums areoperated Yin staggered arrangement; that is to say, each series ofrabbles and pendulums are alternated by fixing the eccentrics 17 indifferent positions on the shaft 19. ln this way, as the ore leaves oneset of rabbles it will be taken up by the succeeding series, and thuspassed von `to the outlet 5, where it is discharged, thoroughly roasted,into the chute 20.

This furnace may be constructed with a plurality of sets of rabblesworking parallel to each other, in a double concaved furnace, as shownin Fig. 5.

|The rabbling mechanism is in the furnace at all times, such .parts asare exposed to 'the greatest heat being hollow, and being supplied witha cooling medium such as air or water.

The passages or openings B in the arch through which the rabble arms 10pass', are built in the form of a segment of a circle, and are closed bymeans of the semicircular pieces 13 of sheet iron that vmove with thestems and slide up and down as the arch may rise or fall from expansionor contraction, and as the travel of-each plate 3 is circular, there isno difficulty in keeping the passage perfectly closed at all times.

Having thus described my invention, what I claim and desire to secure byLetters Patent fis- 1. A reverberatory furnace having feeding anddischarge means at opposite ends,

and rabbling mechanism operable transverse to the length ofthe furnaceand adapted to gradually advance the ore from the feed to the dischargeend, said rabbling mechanism being suspended from a point outside thefurnace and including rabbles of pyramidal for-m having their narrowerends pointing toward the discharge means.

reverberatory furnace having feeding and discharge means at oppositeends, and rabbling mechanism operable transverse to the length of thefurnace and adapted to gradually advance the ore from the feed to thedischarge end, said rabbling mechanism including pendulums extendingthrough the arch of the furnace and suspended from a point there-above,and carrying rabble members of pyramidal form.

A reverberatory furnace having .feeding and discharge means at oppositeends, and rabbling mechanism operable transverse to the length of thefurnace and adapted to gradually advance the ore from the feed to thedischarge end, said rabbling mechanism including pendulum membersextending through 'the arch of the furnace and suspended from a pointthere-above, and carrying removable shoes, which shoes extend lengthwiseof the furnace and are triangular in cross-section and tapered endwise,with the tapered ends of the shoes disposed toward the discharge end ofthe furnace.

4. A reverberatory roasting furnace having its hearth transverselyconcaved, and rabble members extending through the arch of said furnaceand suspended from a `point there-above, said members being operativeacross said hearth in a direction transverse to the ,length of thefurnace.

A reverberatory roasting furnace having its hearth transverselyvconcaved, said furnace having an arch provided with transverse slots,rabble members operative across said hearth in a direction transverse tothe length of the furnace, said rabble members mounted on swingingpendulums, which pendulums operate through slots in the furnace top, andmeans operating over 'the top of said slots and carried by thepend-ulums for closing the slots.

i '6.- A reverberatory roasting furnace having its hearth transverselyconcaved, rabble members operative across said hearth `in a directiontransverse to the length of the furnace, said `rabble members mounted onswinging pendulums, which pendulums operate through slots in the furnacetop, said members vhaving wedge keys engaging slots in the lower partsof the pendulum whereby the members are removably attached, and meanscarried by the `pendulums for closing the slots in the furnace top, saidlast-named means including eoncaved plates on the pendulum membersoperating across corresponding concaved mouths of the slots.

T. A reverberatory roasting furnace having its hearth transverselyconcaved, rabble members operative across said hearth in a directiontransverse to the length of the furnace, said rabble members mounted onswinging pendulums, Which pendulunis operate through slots in thefurnace top, and means carried by the penduluins for closing the slots,said last-named means including concaved plates on the pendulum membersoperating across corresponding concaved mouths of the slots, saidooncaved plates being loosely mounted on the pendulums to adapt them tothe expansion and contraction of the furnace.

8. A reverberatory roasting furnace having its hearth transverselyconcaved, rabble members operative across said hearth in a .with slotsand the rabble members having keys removably engaging said slots, andmeans carried by the pendulums for closing the slots in the furnace top,said pendulums being made hollow and having fluid cooling connections.

In testimony whereof I have hereunto set my hand in presence of twosubscribing Witnesses.

BENJAMIN HALL. Witnesses:

FRANK T. NiLoN, NICHOLAS SNELL.

